1. Field of the Invention
The present invention relates generally to ice anchoring devices, and more particularly to ice anchoring devices such as ice axes, ice daggers, pitons, etc., which are implanted in ice to assist climbers.
2. Description of the Prior Art
One of the more demanding mountain climbing exercises is the climbing of the glaciers and frozen waterfalls. Climbers conventionally use anchoring devices, and particularly ice hammers, to aid in scaling such icy terrain. However, these previous anchoring devices have essentially been modifications of anchoring devices readily adapted to climbing on rock, or constituted, in essence, of enlarged ice picks. In rock climbing, it is conventional to employ tappered anchoring devices which wedge into cracks and crannies. However, when working on ice, the cracks and crannies are created by the anchoring device itself. Because of the brittleness and planes of cleavage in ice, driving of an anchoring device into the ice utilizing an expanding wedge concept has, while operable, seriously compromised the strength of the ice after securing the anchoring device. As with the conventional ice pick, many of the previous anchoring devices were more suited for cleaving the ice into sections, though of course this does not always happen as a result of the mass of ice involved, than in providing secure purchase for a climber by preserving the inherent strength of the ice.
Tubular members, being quite common, have been used as anchoring devices. However, it appears that most the edge of such members has been formed by grinding an external bevel. This of course results in a spreading wedge action when the member is driven. Those with an internal bevel have been troubled with impacted ice in the bore as a result of the reduced diameter of the bore relative to the larger diameter of the edge of the bevel.